#include <iostream>
using namespace std;

int main()
{
    // variables must be declared before they're used
    int x;
      // variable x is visible, usable, "in scope"
      //   from the point of declaration
      //   within the surrounding { }

    x = 5;
    int y = 10;
    cout << x << " and " << y << endl;

    if ( x == 5 )
    {
        int z = x;    // z is in scope within the
                      //   body of the if statement
        z += 3;
        int y = 15;   // this y is DIFFERENT than
        x += 4;       //   the y up on line 13

        cout << x << " and " << y << " and " << z << endl;
    }

//    y = z;    // THIS IS NOT ALLOWED (z is out of scope)

    cout << x << " and " << y << endl;


    return 0;
}